The TileOverlay class is used to add an image overlay on the map. In order to add the image overlay on the map, you should create an TileOverlay object and attached it to the map by the addTileOverlayToMap method. After setting your TileOverlay on the map, it will maintain its geographical position and stretch according to any change in the zoom level of the map.
The TileOverlay constructor. Creates a new TileOverlay instance.
The tile overlay position is fixed to screen (it won’t move in any map dragging).
The anchor and the offsetPosition parameters are used to determine alignment of the tile overlay above the map.
The offsetPosition is relative to the given anchor.